Synthesis and characterization of a conducting polyaniline/TiO2−SiO2 composites

Polyaniline/TiO2−SiO2 composites were prepared by an in situ chemical oxidation polymerization approach in the presence of hybrid TiO2−SiO2 fillers. The obtained polyaniline/TiO2−SiO2 composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and current−voltage (I−V) measurements. SEM picture shows a variation in morphology of polyaniline (PANI) from fiber shape to relatively regular particle shape with increasing TiO2−SiO2 contents in the composites. The floccule-like structures were observed by high resolution TEM, which may help improve the efficiency of conductive network. SEM, XRD, TG, and FTIR spectra all reveal that a relatively strong interaction exist between TiO2−SiO2 and PANI. The I−V characteristics in such composites indicate that the charge transport is mainly governed by the space charge effects, which occurs at the interface between the conducting PANI and TiO2−SiO2. Meanwhile, PANI/TiO2−SiO2 composites exhibit significant increase in conductivity than PANI/TiO2 or PANI/SiO2. The reasons about high conductivity of PANI/TiO2−SiO2 have also been discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2288–2295, 2013